I've got a customers boat in the shop that's getting 2 Kicker 12L7's. I know I've seen a couple pics here of either Chucktronics or Acme Tops and Tunes that did a boat like that, or something similar. I'd like to squeeze both woofers under the helm together. The boat is a 23LSV and does have a heater.

I'm looking for pictures and box dimensions, if anyone does'nt mind posting up some info. Thanks in advance!

I'm looking for pictures and box dimensions, if anyone does'nt mind posting up some info

LOL John your supposed to be a professional Audio install shop. Should people provide detailed instructions on how to do what your being payed for, Sorry man but that's pretty funny. Im all for helping anyone and everyone I can out and do here all the time.

I just found it funny that a few times when I posted pic's of stuff I have done and posted them here your ONLY reply was, " Part Number's" LOL I guess Its my duty not only to provide you (a professional install shop) with a step by step process on how I did what i did & a link and phone number to my contacts LOL

Houston we don't always agree, but your right on there. Grant provides a ton of useful info on here and his post was not entirely untrue. Does seem odd for a professional shop to be soliciting free advice for a install they are charging for. Are they going to pay the guy who posts the winning design?

Sounds to me like he is just doing some research and trying to find some different ideas of what he might want to do. Maybe he has some ideas but wants to see if some other's have better idea's that he might be able to use some portion of.

Houston we don't always agree, but your right on there. Grant provides a ton of useful info on here and his post was not entirely untrue. Does seem odd for a professional shop to be soliciting free advice for a install they are charging for. Are they going to pay the guy who posts the winning design?

So this isn't a public forum? This particular part of this forum isn't for info about boats? I'm confused. So we are all supposed to strictly post pics of boats, parts and accessories and not be able to ask questions about them? I've been a part of wakeworld for 4 years and lurked for years before that and it seems as if everyone is waaayyy uptight now on here. Maybe Jonyb wanted ideas for an application the customer was asking for? So that customer doesn't have an experience like the guy who posted the thread about if the stereo shop should replace his box or not. Back on track with this thread.

Sounds to me like he is just doing some research and trying to find some different ideas of what he might want to do. Maybe he has some ideas but wants to see if some other's have better idea's that he might be able to use some portion of.

Grant, you're right, I AM supposed to be a professional shop, but that doesn't mean I know everything, LIKE YOU DO. I'm not from Brolifornia, and **** like this doesn't grow on trees. We also aren't total f8cking pricks like you either. Thanks for stopping by in my thread though. What would it be without your smartass attitude belittling everybody?

Nick, I disagree with the 99%, it's a lot less if you pay attention.

The boat owner is in this thread, he's trying to find something he likes the best. If you guys don't like providing information, I'm sorry. I help out with tech support on other forums a lot more than here. Do I get paid for it? No. Do I expect it? No. I do, however, look for help too. Because after all, NO ONE is perfect and NO ONE knows everything. My shop doesn't do a lot of big custom installs like this.

I'm in KY, people don't spend big money on flashy installs.

Thanks for all that posted with ideas. I'm not a JL dealer. I don't have specs on these boxes, and I don't want to call JL and fight with them.

My buddies 23LSV has a single 12 in a slot ported box done by Acme and his boat does not have a heater. I would think about a single in a ported box, I doubt you will get close to spec on those woofers in that space. Minimum recommended volume for that sub in a vented box is 1.75 cubes X 2 = 3.5 and I would say that about 1 cubic foot more than you will be able to fit. I guess you can run them in a 0.88 x 2 sealed box, that would be the safest configuration in that space. You will probably need to jog around the heater. Alternatively you might be able to relocate the heater to right behind the driver or farther forward under the bow storage but I think you will still be pressed to get much more than 2.5 cubic feet in that space. When my buddy went from a single 12 in a sealed box to a single 12 in a ported box it made a huge difference, seems like 3x the bass not 2x. It was the same ARC 1000 watt amp on both. I think Ryan from Chucktronics prefers to put two of the 10" DD subs firing into the walkthrough in the 23LSV. As you know you will want to try to keep the subs firing from the same location to avoid cancellation.

John,
First you have to get the 12L7 Thiele/Small parameters. You at least need their recommended internal gross enclosure volume. You'll simply double that displacement for two woofers. Phil with Kicker is on here frequently and extremely helpful. I would PM Phil to get the info or direction to the right resource.
From there the boat will determine the maximum external enclosure dimensions and shape. If the enclosure gets at all complex you can contact me after you have collected the basic info.
If you end up a bit lite on displacement you can use polyester fiberfill damping to adjust for this, but only to a degree. You really need to obtain 85/90% of the optimum enclosure.
This particular woofer carries a lot of moving mass so it does extremely well and goes very deep in a sealed box. Ported will give you more output but will make a single enclosure to facilitate two 12s huge and very difficult if not impossible.
Also, as Mike pointed out above, you do not want to do an unusual orientation scheme just to force things to fit. Whether both are opposing and side-firing or side-by-side and direct radiating, you will want the subs oriented in a symmetrical manner.
You might have to adjust to dual 10s. The boat should be the deciding factor before all else.

We also aren't total f8cking pricks like you either. Thanks for stopping by in my thread though. What would it be without your smartass attitude belittling everybody?

You're a professional and/or own a shop... way to carry yourself.

Quote:

Quote:
Originally Posted by sidekicknicholas
Disagree, 99% of the time G is nothing but nice and helpful.
Quote:
Originally Posted by murphy_smith
Grant you win the award for being the biggest DICK on the website....You must feel like a big boy always putting people down from behind your keyboard
Grant is absolutely a dick, unless its one of his blingtastic threads...long live the King of Bling

He has always been helpful on threads I've been apart of... poor grammar and spelling, but helpful.

On a thread related note....
Are the ballast tanks in (whatever year the guy has) hard tanks under the floor? If they don't plan on running additional ballast it either side of the engine might work well.

man i F'ing love audio! acme does some awesome stuff! Good luck john post some pics of your install along the way and turn this thread into a good instructional while youre at it! I'd like to think that pro or not we can all learn something from each other here, as that is pretty much the point of having this place. Its a forum to bounce ideas off of each other and give the confidence to tackle projects we might not otherwise. Keep it positive folks, If we all got together over sodas and beers instead of keyboards and computer screens i'm sure everyone would get along just fine.

Additional ballast is a must with this boat. All the equipment is at the shop and payed for. dont think want to spend more money on speakers then try to sell the other stuff. Ported would be nice, but if it can't fit sealed should be fine. I'm sure 2 12's should be loud enough in a sealed box.

I'd like to think that pro or not we can all learn something from each other here, as that is pretty much the point of having this place. Its a forum to bounce ideas off of each other and give the confidence to tackle projects we might not otherwise.

I almost had to go out and get a soda and popcorn before reading this thread....

for a pair of L7 in a vented box, the smallest you will want to go is 3.5 cu. ft, NET, (meaning you gotta add to that box volume to equal the displacement of the port if the port is going to be internal. For that Vb, (sorry, box volume) you want to have a port that has 66 sq. inch of port area, with a length of 23 inches, which wil take up another cubic foot inside your enclosure.

The big box will be 6.5 cubic feet woth a port that has an area of 79 sq. in. and a lngth of 20 inches. Grossed up the box will be 7.5 cubic feet. Do you have that much room?

Otherwise, a sealed enclosure is going to be somewhere between 2 cu. ft. and 4 cu. ft.

Something tells me that the big vented box is not going to work.... I bet you can get the smaller vented enclosure in there, but the design might be interesting, especially considering the port.

Phil, if it were up to you with these particular speakers what setup would you go with? I'm doubting very seriously the big box is going to fit. So between the smaller ported box and a sealed box which would be your choice?

The smaller vented box is often going to sound worse than a same-size sealed box. As a ported box gets smaller and smaller, the port gets longer and longer, or the area goes down, (port velocity goes up) for any given Fb, (sorry, Box Tuning Frequency). The very small ported box will not be appreciably louder than a same-size sealed box, and the probability of port noise due to the smaller port area is quite real.

Given your probable scenario, with two L7 woofers, I would build as large as I could and make it sealed.

An option to consider might be to use each in its own box. Fire them into each other, with about a 4" to 6" distance from woofer face to woofer face. Use plexi windows in the sides of the boxes to show off the motors and cast baskets. You can trim out a facia board that makes it look like you have a giant port coming right out of the middle, but it is not all complex like a bandpass design...

Manifold loading like this makes for a crude acoustical transformer and can often increase SPL and lower resonance. The modeling of the slot/manifold loading is imprecise, especially in a boat, so you could build the two separate boxes, then play with the gap between the two until you got what you like, then build a facia board to tie it all together and dress it out.

David, or anyone that actually knows. Are you saying that if the speakers are in a single enclosure that they need to fire the same direction or noise cancellation occurs? Currently I have a sealed box with one firing forward and one firing sideways (because of space), I wonder if I should change it?

David, or anyone that actually knows. Are you saying that if the speakers are in a single enclosure that they need to fire the same direction or noise cancellation occurs? Currently I have a sealed box with one firing forward and one firing sideways (because of space), I wonder if I should change it?

Unless they are separated by a distance of several feet, they will not cancel due to not being mounted on the same plane or box face. There is however a chance that there is some phase cancellation due to un-equal loading. Say for example one is tightly placed next to a side wall while the other is firing staright out into the cockpit area. The mass loading of that slot will cause that woofer firing into the side wall to behave differently than if it were facing straight out into the listening environment.

There may be zero cancellation, but your bet is best when building a box to try to get both woofers loaded similarly. If you can face them forward like Ian'a above, do that. If you have to fire one woofer into a wall due to space, consider firing both woofers into a wall, with a simialr distance separation.

Hope that answers? Others might add too, so mine is not the only right answer.

Thanks Phil, that was what I was looking for. Both woofers are loaded pretty equal because they fire off separate walls. Can someone tell me the ideal way of facing an enclosure in the underhelm situation? Whether it being ported or sealed, I've had better luck firing into a wall instead of directly out into open air, but maybe others found out something better? Ive done many car enclosures over the yearsbut not many boats so I could learn from others testing!

Ryan, my last Supra, and a few other boats we've done, sounded great with a big 12 firing out from under the helm - provided the enclosure was correct. The box that that David speaks of - I did that in a Caddy CTS-V that I once owned. 2 DD 8's fired into a center chamber that had a 6" port pointing through the rear deck (OEM sub was removed). It really sounded like something more than 8's, but only sounded good with certain music.

Let me add another scenario to Phil's example.
Let's say the first woofer is direct radiating into the cockpit. The second woofer is side-firing against the hull and into the under-helm cavity. The second woofer 's phase response is a summation of the woofer, enclosure, distance differential and under-helm cavity (which stores and filters energy based on the size and compliance). Now the output of the two identical woofers are smeared. Is it the worst thing considering the wavelengths of subwoofers? No. By why contribute to an asymmetrical phase response if it can be so easily avoided.
Here is another scenario.
Let's say the width situation is challenged to get side-by-side woofers but there is a ton of front to rear depth, so the designer runs two down-firing subs with one in front of the other. In this restrictive situation the two subs are loading into a very different air mass and compliance. One sub is more loaded by the other. The final Qtc of the two subs may be different.

The simple lesson from these scenarios is to keep it basic and symmetrical. Also, stay away from overly complex enclosures that are extremely elongated or have extreme appendages in order to satisfy a displacement requirement, particularly on a bass-reflex enclosure.

My dual woofer design idea is much like Phil's, except that I would have both subs sharing a common enclosure, magnet to magnet, and both subs side-firing outwardly, one aimed at the outside hull and the other aimed at the interior walk-through wall of the helm. There would be less construction material, and I could use the natural void to exhaust the radiation that is likely to be on each side of the enclosure making the entire enclosure smaller. The facade would have a single window to view both subs. There would also be less reduction in the radiating surface area of the collective subs without the center manifold and by using the outside space. The enclosure would be positioned to equalize and average the space to each side. The two woofers would be symmetrically loaded in respect to the boundaries and the output would benefit from the boundaries.

Lots of options as long as you stay with the core principles and do not try to force fit a larger woofer into a compromised enclosure.

If using your side firing enclosure, and lets say there is much space above the enclosure where the helm is. Would it be best to allow the subs to radiate into that space or should it be blocked off so that sound waves travel out instead of up into that space? The reason I ask is that I've seen a few (including mine) with large open areas above the enclosure that might negate potential of the enclosure and space.

Ryan,
The size of the cavity is a real concern. If the under-helm cavity adjoins to the under-bow seating consoles then it would be ideal to seal that bow compartment off. The larger the cavity the greater the compliance and the greater the absorbtion and the longer the delays are of the energy reflected out of that area. With longer delays the reflected energy out of the compartment is farther out of phase with the direct radiation of the woofer. In this case distance becomes secondary to the volume of the space.
Now if the under-helm compartment volume is limited to the helm console then much of this smaller cavity is consumed by the sub enclosure. The ratio of venting (open area over the top of the enclosure/facade and around the enclosure) is very positive as compared to the cavity displacement. In this scenario there is very little compliance in the smaller cavity and there is very little resistance in the radiation path. Then add in the five boundary surfaces of the helm interior cavity that reinforce the bass energy. Those reinforcing planes are a real plus and welcome leverage in an open field.

David, I love those answers but maybe you can dumb things down a bit so we don't have to read it 4 times to understand it! lol

Yes the helm and bow are connected, last year I stuffed a blanket in the whole in hopes to seal it off. Im not sure if my ghetto solution was adequate to fix the issue. Should I do something different? The cavitiy under the helm is large enough that I can sit up straight (not while the box is installed) but it is rather large and still has lots of space when the box is installed. The box I'm using is a 2.2cuft sealed enclosure with two 12's. One is facing the back wall and the other fires at the exterior side. I'm just not sure if all that extra space is helping or hurting my efficiency?

Ryan,
You asked a very difficult question to answer. It's not an easy thing to script.
Now that you have been more specific with your situation I can change course and tell you exactly what to do.
The blanket just absorbs energy. You want to avoid that.
Create a resin coated 0.75" thick birch partition between the driver's helm console cavity and under bow area cavity. Close off the bow to make the entire cavity smaller. Use aluminum 'L' bracketry or birch/HDPE blocks/strips to fix the partition in place. It might take some overlapping sections to get a tight fit and good seal.
Or, to get a perfect seal you can tape/foil/tarp everything off and use a marine 2-part expansion foam as a perimeter gasket. The right 2-part expansion foam will not melt down when you apply polyester fiberglass resin. So you can apply a layer of fiberglass mat to both sides over the foam to finish the perimeter of the partition and add rigidity. Then carpet over the panel. This is one way to go about it.

I didnt read everyone's post on here before posting so I may be repeating some info. I saw a few posts by people that I consider to have a lot of tech/fab experience but tend to fall on their face when their egos get the best of them....anyway, I'll look the other way and try to contribute.

I put one 12" L7 in my 2007 247 lsv with a heater over the winter this year. Here are a few things that I learned/found out while I was researching for my setup...

- I got a ton of info from jaxonboats off of malibucrew. He was even kind enough to send me dimensions and pics of the crazy box that he made.

- I went into this project trying to keep everything as "factory looking" as possible. Examples include carpeting my new kick panel and keeping the kick panel location and angle.

- I think I read/saw where there was more room under the dash in the 23 lsv vs the 247. I realize that this doesn't make sense given the sizes of the boats but hopefully it's a plus for you.

- I did not make my box like jaxonboats made his. My box looked like a simple rhombus (side view) made out of 3/4 mdf, resin coated, liquid nails sealed, and within a tenth of a cubic foot of the minimum vol requirement per the speaker's spec sheet.

- make a cardboard mock up of the box before actually making the real box. This takes some time, but will save some headache.

- Having an angle finder is a must for maintaining the factory angle of the kick panel.

- I had to remove the starboard storage compartment that is in the walk way to the bow area when I installed the L7 speaker box.

- The curvature in the floor that leads to the starboard wall of the boat kind of makes things a little difficult, as well.

I m sure there is more but this is all that I can think of 3 months later...Personally, I think that you're gonna have to give up some leg room in order to get the box dimensions correct. I don't know exactly how much more room is in the 23, if any, but this seems tough....

Jeff, thanks for the post. I appreciate you taking the time to offer valuable info on something like this.

We managed to squeeze the 2 12's into a sealed enclosure with the perfect amount of air space, and not lose a whole lot of room. There was an existing box that we took out that had 1 10W6 in it, and I think Chase actually gained legroom going to what he has now.